The latest British Full Monty wannabe is a totally made up true story about how some Cornish fishermen singing sea shanties became pop stars. It's a Pinocchio narrative: a bunch of 2D caricature Lunduners (music biz types just to strip them of any shred of humanity) go on a stag do to Port Isaac, Cornwall and rub some propr, genuine, 3D local people up the wrong way. But one of them stays behind, goes native, rejects city ways and becomes a real boy.

The appeal of the music is that it is authentic and totally without contrivance. Its tale is told in a narrative full of all the standard plot contrivances British cinema applies to its output of romcoms and plucky underdog tales. There's the vital community hub (in this case a pub which is going bankrupt, even though it is always packed with heavy drinkers) that is threatened by unscrupulous outside developers, and the unspoilt, local love interest (Middleton) who initially despises her out-of-towner suitor (May.) It's like Local Hero written by a committee. The plotting is guileless and the jokes obvious. It also has some product placement for a Cornish IPA that is Bond movie blatant.

And yet, and yet, the cast almost make it work. Granted, the usual top-notch Daniel May doesn't really work in the lead role but all those playing locals are splendid. I was even convinced by their accents. Performers with names like Purefoy and Tuppence must be accustomed to being cast in British films about people who can chase their ancestors back for generations, but not when those ancestors spent their lives in a single village working the sea. They are both exceptional though. Purefoy, as the fishermen's leader, has a gritty antagonism while delivering the humour. The fish he catches go well with the chips on his shoulders. Middleton has been turning up like a bad Tuppence in films and TV shows for over a decade without making any great impact but here she is radiant and charming enough she would have Hugh Grant himself spraying his juice. This could easily be her breakout role. Maybe she'll lending a bit of class to a Star Wars or Marvel ensemble in a few years time.

I think you'd need to feel overly indulgent to enjoy this film, but these performers are perhaps worth indulging.